@lhwoz I think others on here have said it perfectly- and probably have more experience than I do- but I can share mine too. First, so sorry you are experiencing this as I know firsthand how terrifying the pains were- the anxiety of the pains were worse than the lumpectomy and reexcision (and radiation) that I had. Wondering if something came back.
I messaged my surgeon’s office, asking if I needed to come in for a scan or exam (I think my sharp pains started even before radiation - they are very random.) she reassured me that this is very normal and it is not uncommon for it to happen a year or more after surgery.
I am almost a year out now from the first lumpectomy now and the sharp random pains have gotten fewer and farther in between.
I cannot speak to the other issues you’ve experienced, but can say for radiation skin help during treatment, I used a combo of clear aloe gel and Active skin repair gel (brand). I still use the combo on and off now when my skin is itchy or dry- it prevented damage for the most part, which I did not expect as I have extremely sensitive skin.
I wish you well in your recovery!